File:STEREO views Comet Pan-STARRS.jpg

English: Nothing else has seen Comet Pan-STARRS like this: the comet posing with earth itself, seen from the STEREO Behind spacecraft. Following in earth's orbit, the spacecraft is nearly opposite the sun and looks back toward the comet and earth, with the sun just off the left side of the frame. At the left, a substantial coronal mass ejection (CME) is erupting from a solar active region. The comet is way in the foreground of this image from the spacecraft. The processed digital image is the difference between two consecutive frames from the spacecraft's SECCHI Heliospheric Imager, causing the strong shadowing effect for objects that move between frames. Objects that are too bright create the sharp vertical lines. The processing reveals complex feather-like structures in Comet Pan-STARRS caused by dust particles. The ion tail is the thin one that's pointing almost radially away from the sun.